Hydrodynamic characteristics of porcine aortic valves cross-linked with glutaraldehyde and polyepoxy compounds

Porcine aortic valve (AoF) tissues cross-linked with glutaraldehyde and epoxy compounds were reported to have high anticalcification properties, but their hydrodynamic characteristics have not been evaluated. The aim of the present study was to investigate the hydrodynamic differences between porcine AoFs, cross-linked with concomitant use of an epoxy compound and glutaraldehyde, at different fixation periods. The valves were mounted on a pulsatile flow circulation mimicking a left heart. The left atrial and left ventricular pressures and mitral and aortic flows were measured at every 0.002 seconds, and the hydrodynamic factor of the valves mounted on the mitral position was estimated. Effective orifice area and the regurgitation volume, which are used as indicators of valve efficiency, failed to detect significant differences due to glutaraldehyde fixation time. In addition, the pressure gradient across the bioprosthetic valve and the variation of mitral flow also had no significant differences. The flow circuit model of the present study was mimicking of a left heart. The evaluation of the mitral valvular function with different glutaraldehyde fixation times was accomplished by relating the pressure with the flow, and by estimating the time lag between valve motion and transvalvular flow.